Article washing apparatus



United States Patent 3,375,835 ARTICLE WASHING APPARATUS Charles R.Lopp, White Bear Lake, Wilbur G. Peyer, St. Paul, and James G. Ruspino,White Bear Lake, Minn., assignors to Whirlpool Corporation, acorporation of Delaware Filed Sept. 23, 1965, Ser. No. 489,533 4 Claims.(Cl. 134-176) ABSTRACT OF THE DISCLOSURE An axial flow liquid pump for adishwasher provided with a spray arm and having a portion of its housingintegral and rotatable with the spray arm.

This invention relates to an article washing apparatus such as adishwasher and relates particularly to an improved liquid distributingsystem for circulating liquid over articles being washed.

Automatic dishwashers in which dishes or other articles being washed areplaced in racks in a tub or wash chamher and sprayed during variouscycles with detergent solution and rinse water are quite common. One ofthe features of this invention is to provide an improved dishwasher ofthis type comprising a tub for containing liquid, article retainingmeans in the tub, liquid distributing means in the tub for distributingliquid over the retaining means and articles retained therein and pumpmeans for forcing liquid from the tub through the distributing meansincluding a pump housing communicating with the liquid distributingmeans.

Another feature of the invention is to provide such an improveddishwasher in which a liquid impeller is used for distributing liquidand the distributing system alsoincludes a housing around the impeller,first and second liquid distributing means for distributing liquidthrough different portions of the tub and over articles containedtherein and conduit means connecting the first and second liquiddistributing means with the pump housing, the conduit means and bothdistributing means being interconnected for joint rotation.

A further feature of the invention is to provide such an improvedapparatus in which the liquid distributing system including the liquiddistributing means, pump housing and conduit are suspended from amotorized driving means within the tub, the impeller being rotated withthe rotatable driving means and the first and second liquid distributingmeans, pump housing and conduit being rotatable on the motorized drivingmeans.

Other features and advantages of the invention will be apparent from thefollowing description of one embodiment thereof taken in conjunctionwith the accompanying drawing, the single figure of which is afragmentary, vertical sectional view through a dishwasher embodying theinvention.

The dishwashing apparatus shown in the accompanying drawing anddescribed herein is the complete unit of a dishwasher including theliquid distributing system and a garbage grinder. The garbage grinderand dishwasher combination is disclosed and specifically claimed in thecopending application of Charles R. Lopp, Ser. No. 498,- 850, filed Oct.20, 1965, assigned to the same assignee as the present application.

The dishwasher disclosed in the accompanying drawing comprises a tub 11having a top 12 that is provided with a raised peak 13 at approximatelyits center. The bottom of the tub 11 is provided with a sump 14 also atapproximately the center.

Beneath the tub 11 the apparatus is provided with a motorized drivingmeans comprising an electric motor 15 having a shaft 16 rotatable in abearing 17. The upper part of the vertical shaft 16 above the bearing 17is attached to a drive sleeve 18 by a transverse pin 19'.

The drive sleeve 18 has attached thereto an impeller 20 for providing adrain pump. Surrounding this impeller 20 is a generally cylindricalshredder ring 21 of the usual type for grinding solid materials thrownthereagainst by the rotating impeller 20. Thus, the impeller andshredder ring operate as the usual garbage disposer in grindingrelatively large solid pieces into smaller particles which are flushedto the sewer with the drain water.

The bottom of the drain impeller is recessed and contains therein a seal22 that is located around the drive sleeve 18.

Immediately above the shredder ring 21. that surrounds the drain pumpimpeller 20 is a drain filter 23 having an open center 24. Above thisdrain filter 23 isan inlet difluser 25 having radial vanes 26 integralwith a bottom outwardly flaring skirt 27 provided with spaced inletopenings 28. The inlet diffuser, as stated, is positioned above thedrain impeller and beneath a pump impeller 29. The pump impeller 29 isdriven from the motorized driving means shaft 16.

The pump impeller 29 is mounted on an impeller shaft 32 which isattached to the top of the drain impeller 20.

The hub 35' of the impeller 29 that surrounds the shaft 32 is used tomount the liquid distributing means comprising the lower spray arm 36which includes the usual pair of laterally extending arms 37 and ahollow hub 38 which functions as a pump housing surrounding the impeller29 with both cooperating to provide a pump means.

The hollow hub 38 has a top mounting part 39 with spaced liquid flowopenings 40 therearound with this top part serving to mount the unit onthe upper end 41 of the impeller shaft 32. The spray arm assembly ofarms 37 and hub 38 is thus rota'tably suspended. from the top end 41 ofthe shaft and the spray arm assembly 36 is rotatable about a bearing 42on this upper end 41 by the usual reactive force of the outwardlysprayed liquid as indicated by the arrows 43. The assembly is locked inposition on this upper end 41 of the shaft 32 by a retaining ring 44attached to the upper end of this shaft. Between the retaining ring 44and the upper end of the mounting part 39 there is provided a thrustwasher 45. f

The lower end of the hub 38 is provided with an outwardly flaring skirtportion 46 surrounding the pump impeller 29 and extending therebelow.The skirt 46 is located immediately above the inlet diffuser vanes 26and provides a bottom opening for passage of liquid from the top to theimpeller.

'As previously mentioned, the retaining ring 44 and thrust Washer 45 arelocated on the upper end 41 of the impeller shaft 32. The portion ofthis shaft 32 between the hub 35 and the top mounting part 39 is alsoprovided with a retaining ring 47 and a thrust washer 48.

The drain impeller 20 is surrounded by a lower pump casing 49 having anupwardly and outwardly flared flange 50 that is fastened to the bottomof the sump 14 to span an opening 51 therein and thus form apart ofthebottom of the sump. This flange 50 and thus the lower pump casing isheld in position by a series of circularly arranged screws 52 engagingthe flange 50' and the adjacent annular part of the bottom of the casing11. As can be seen in the single figure, this arrangement provides thatthe lower part of the unit which includes a drain tube 53 is beneath thetub 11 but above the motor 15.

The outwardly and upwardly flared flange 50 on the lower pump casing 49provides an annular opening to the inlet diffuser and thus upwardly tothe pump chamber containing the pump impeller 29 and defined by thedepending skirt portion 46 of the spray arm assembly 36. The spacedvanes 26 provide for even how of liquid into the pump impeller 29.Because the openings 28 in the skirt 27 of the diffuser 25 providedownward access to the drain impeller the annular inlet openings 54 tothe pump casing 49 provide for flow both upwardly into the pump impeller29 and downwardly into the drain impeller 20. As can be seen from thedrawing, the two impellers are vertically aligned with the pump impellerbeing above the drain impeller.

Surrounding the bottom of the inlet diffuser in the region of the lowerpart of the vanes 26 is a recirculation filter 55. This filter has aflexible rubber top 56 surrounding the depending skirt portion 46 of thespray arm assembly 36 and a screen bottom 57 that extends across theinlet defined by the vanes 26 to the reciprocation pump impeller 29.

The inlet diffuser 25 is provided with an annular mounting flange 58that is attached to the upper surface of the lower pump casing 49 as bya plurality of attaching screws 59.

The motor 15 is of the type that can be rotated in either of twodirections. When rotated in one direction the recirculation pumpimpeller 29 recirculates liquid in the tub 12 in the manner to bedescribed hereinafter. When rotated in the opposite direction the drainimpeller 20 pumps liquid from the tub 11 through the drain tube 53.

Mounted above the lower spray arm assembly 36 or first liquiddistributing means is a conduit means whose lowest part is a generallycylindrical flow nozzle 60 having a vertical central passage 61. Anannular center tube retainer 63 is attached to the bottom of a verticaltube 64 by means of a set screw 65. This tube at an intermediate areathereon has an outwardly extending annular flange 66 which bears againsta top bearing 67 around the tube 64. A bottom bearing 68 similar to thetop bearing 67 is held in position against the top of the center tuberetainer 63. These bearings 67 and 68 and thus the tube 64 are held inplace by an upwardly extending wire framework 69 mounted on the firstarticle retaining means, here shown as a bottom dish rack 69a. Extendingbetween a bottom connector flange 62 and the center tube retainer 63 isan expandable and contractible bellows connector 70, preferably made ofa flexible plastic material. The top of the connector 70- is held inposition on the bottom of the tube 64 by means of a clamp ring 71. Thebottom of the connector 70 is held in position by frictional contactwith the connector flange 62. Positioned in the lower end of the centertube 64 is a flow straightener 72 that is provided with a verticalinternal vane 73. The flow straightener is intended to convert therotational components of flow entering the bottom of the tube 64 toapproximately axial flow.

Mounted on the upper end of the center tube 64 as by screws 74 is asecond liquid distributing means, here shown as a top spray arm 75 alsodesigned to be rotated in the customary manner by the reactive force ofliquid jets issuing from the spray arm 75 in the normal manner at anangle as indicated by the arrows 76. Also, some rotation is imparted toarm 75 through the frictional engagement of connector flange 62 and flownozzle 69. The liquid spray is thereby projected toward and overarticles such as dishes (not shown) held in a customary second articleretaining means, here shown as an upper dish rack 77 similar in itsfunction to the bottom rack 69a.

Centrally of the upper spray arm 75 and aligned with the vertical tube64 is a nozzle 7 8 having an outlet opening 79 at the top thereof forprojecting a jet of liquid (not shown) toward the tub top 12.

Mounted on this top 12 at the raised peak 13 thereof which is directlyabove the nozzle opening 79 is a rotatably mounted spray device orspinner 80. This spray device is rotatably mounted about the verticalaxle 81 and is of generally inverted cup-shape with a generally annularrim 82 provided with spaced vertical vanes 83. The spray device 80 isprovided with an upwardly and outwardly sloped bottom 84 of generallyinverted cup-shape sloping from the axle 81 toward the rim 82. The axle81 is located vertically approximately directly above the nozzle opening79.

The apparatus of this invention when used to wash dishes or similararticles operates in the following manner. The liquid, whether detergentsolution or rinse water, gathers in the sump 14 at the entrance 54 tothe pump impeller 29. During the dishwashing portion of the cycle themotor 15 rotates the shaft 16 in a direction such that the recirculatingpump 29 draws the liquid in and forces a portion of it up the hub 38into the lower spray arms 37. The reaction of the sprays 43 and thefrictional engagement of connector flange 62 and flow nozzle 60' causesthe spray arm assembly 36 to rotate and spray dishes and other articlesin the lower rack 69a. The recirculation pump 29 forces another portionof the liquid up through liquid flow openings 40 above the impeller 29and through the flow nozzle passage 61 and the bellows connector 78 intothe tube 64. From the upper end of the tube 64 this portion of theliquid then has one part flowing outwardly through the top spray arm tospray the bottom of dishes and other articles in the rack 77 and anotherportion flowing vertically in a jet out the nozzle opening 79 to thespray device or spinner 80. This jet strikes the spinner at about thecenter axle 81 and the liquid force is diverted by the cup-shapedinverter bottom 84 toward the annular rim 82 and the spaced openings 83therein. The portion of the liquid issuing through the vanes 83 causesthe receiver 88 to spin about its axle 81 and spray the tops of articleswithin the rack 77 and spray the inner surface of the tub top 12 toprevent the ac cumulation of soil thereon.

During this dishwashing operation of the apparatus large solid particlesare gathered on the bottom filter screen 57 that is beneath therecirculation impeller 29. Because the rotation of the motor shaft 16 inthe direction for washing, as previously described, has the effect ofrotating the drain impeller 20 in an opposite direction from its normalpumping direction of rotation, the drain impeller sets up a liquid flowpath from inlet openings 28 downwardly through open center 24 of drainfilter 23 and upwardly through filter 23 to pump impeller 29. Since theopenings of filter 23 are substantially smaller than those of filterscreen 57, filter 23 removes the small food and dirt particles from theliquid flowing therethrough. A liquid flow path is simultaneously set upfrom impeller 20 through openings 21a in shredder ring 21 to inlet 53aof drain tube 53. A vortex flow results at inlet 53a, in drain tube 53and in hose 53b, as liquid is centrifugally ejected from pump casing 49ramp, The small particles in the liquid flowing to tube 53 and hose 53bseparate from the liquid and are deposited in hose 53b. As the liquidloses its velocity, it is returned to pump impeller 20 through the lowpressure area in the center of the vortex. Furthermore, the upward flowof liquid from drain impeller 20 aids in depositing the large solids onthe filter screen 57. At the completion of the washing operation, theapparatus goes through a drain operation in which the liquid is drainedfrom the tub and the large solids collected on the filter screen 57 andthe small particles collected on filter screen 23 are directed toimpeller 20 to be ground up as in an ordinary garbage disposer forpassage into the sewer with the liquid. During this drain and garbagegrinding portion of the machine cycle the apparatus operates as follows.

During the drain and garbage grinding operation the direction ofrotation of the motor shaft 16 is reversed by reversing the direction ofmotor 50. This causes the recirculation impeller 29 to rotate in anopposite from normal direction with the result that liquid from theimpeller 29 is pumped downwardly to backwash the screeen 57 and forcethe large solids through the central opening 24 in the drain filter 23.Simultaneously, the small particles are flushed from the underneath sideof the drain filter 23. After being forced past the drain filter 23 theliquid and the small particles are pumped out the drain tube 53 to thesewer or other place of disposal, and at the same time the drainimpeller 20 shreds the large pieces of solids to fine particlesagainstthe shredder ring 21.

In the apparatus of this invention the recirculation pump 29 and thedrain pump 20 and associated parts can be assembled as a package unitand installed in the tub 11 as a unit. These parts include all theelements from the motor 15 up to and including the retaining ring 47. Asmentioned previously, the drain filter 23 provides a means for trappingand holding small solids during the wash operation in order to decreasethe redeposit of these small particles on the articles being washed.During the pumpout operation in which the solids are ground to fineparticles by the drain impeller and the shredder ring 21, any solidsgathered on the filter 23 will be flushed therefrom. The result is thatthe filter is automatically cleaned during each pump-out and garbagegrinding operation.

In the illustrated apparatus all of the parts from the connector flange62 through the top spray arm 75 may be subassembled as a unit andmounted on the lower dish rack 69a. The connector flange 62 and thebellows connector 70-function to provide a flat, non-jamming contactseal surface between the bottom of the connector flange 62 and the topof the flow nozzle 60. The bellows connector 70 being made of flexiblematerial provides flexible compression contact between the flange 62 andthe top of the flow nozzle. This seal is provided by the lower spray armassembly 36 rising to meet the connector flange 62 when subjected tointernal water pressure in the lower spray arm assembly.

The pump casing 49 also serves as the end bell for the motor 15 beingheld in place thereon by spaced bolts 85. The face of the drive sleeve18 contacts the face of the motor bearing 17 as shown at the bottom ofthe drawing so as to provide a thrust bearing structure for thisassembly I As described above, the article retaining means in the tub 11is embodied in a first retaining means here shown as the lower rack 69aand the second retaining means shown as the upper dish rack 77. Thefirst liquid distributing means of the distributing system is embodiedin the lower spray arm assembly 36 which is positioned immedi atelyabove the bottom sump. The second liquid distributing means comprisesthe upper spray arms 75. The pump means which forces liquid through thedistributing system comprises the impeller 29 and the rotatable pumphousing that terminates in the bottom skirt 46. The pump casing performsa number of functions. Thus, it provides a bottom inlet to the impeller29 and a discharge housing from the impeller to the distributing system.Because the higher pressures from the impeller 29 are at the peripherythereof this portion of the impeller communicates with the lower sprayarm assembly 36 so that articles in the lower rack 69a will receive amore vigorous liquid action. The area adjacent the center of theimpeller 29 is subjected to lesser pressure so that this portion of theimpeller communicates with the vertical conduit including the tube 64for conveying liquid upward to the upper spray arms 75 which comprisethe second liquid distributing means. Thus, articles in the upper rack77 or second article retaining means are subjected to lower liquidpressure and thus a more gentle action...

The apparatus of this invention provides an eflicient and direct meansof connecting a pump discharge to a distribution system and provides amore thorough distribution of resultant liquid fiow throughout the tub.Furthermore, this discharge may be used to apply liquid to differentsections of the tub such as the two shown in the specific embodiment andmay be used to subject the different sections to different liquidpressures in the manner described above.

Having described our invention as related to the embodiment shown in theaccompanying drawing, it is our intention that the invention be notlimited by any of the 6 details of description, unless otherwisespecified, but rather be construed broadly within its spirit and scopeas set out in the accompanying claims.

The embodiment of the invention in which an exclusive property orprivilege is claimed is defined as follows:

1. Article washing apparatus, comprising: a liquid containing tub havinga bottom liquid collecting sump; a first article retaining means in saidtub adjacent said sump;.a second article retaining means in said tubspaced above said first retaining means; first rotatable liquiddistributing means in said tub for distributing liquid over saidretaining means and articles retained therein located adjacent saidfirst retaining means; second rotatable liquid distributing means insaid tub for distributing liquid over said retaining means and articlesretained therein located adjacent said second retaining means; pumpmeans for forcing liquid from said tub through both said firstdistributing means comprising a rotatable impeller having a center and aperiphery, both said liquid distributing means including a pump housingportion surrounding said impeller; means for directing liquid flow fromadjacent said periphery to said first distributing means for highpressure distribution of liquid to said articles; and means fordirecting liquid from adjacent said center to said seconddistributingmeans for low pressure distribution of liquid to saidarticles comprising conduit means having an entrance adjacent saidimpeller center and an exit communicatingwith said second liqiuddistributing means.

2. Article washing apparatus, comprising: a liquid containing tub havinga bottom liquid collecting sump; a first article retaining means in saidtub adjacent said sump; a second article retaining means in said tubspaced above said first retaining means; motorized driving means withinsaid tub; first rotatable liquid distributing means in said tub fordistributing liquid over said retaining means and articles retainedtherein located adjacent said first retaining means and supported fromand rotatable on said driving means; second rotatable liquiddistributing means in said tub for distributing liquid over saidretaining means and articles retained therein located adjacent saidsecond retaining means; pump means for forcing liquid from said tubthrough said distributing means comprising a rotatable impeller having acenter and a periphery supported on and driven by said driving means,said liquid distributing means including a pump housing portionsurrounding said impeller and forming a part of said first liquiddistributing means; means for directing liquid flow adjacent saidperiphery to ing means for high pressure distribution of liquid to saidarticles; and means for directing liquid from adjacent said center saidsecond distributing means for low pressure distributing of liquid tosaid articles comprising conduit means having an entrance adjacent saidimpeller center and an exit communicating with said second liquiddistributing means.

3. Article washing apparatus, comprising: a liquid containing tub havinga bottom liquid collecting sump; a first article retaining means in saidtub adjacent said sump; a second article retaining means in said tubspaced above said first retaining means; motorized driving means withinsaid tub; first rotatable liquid distributing means in said tub fordistributing liquid over said retaining means and articles retainedtherein located adjacent. said first retaining means and supported fromand rotatable on said driving means; second rotatable liquiddistributing means in said tub for distributing liquid over saidretaining means and articles retained therein located adjacent saidsecond retaining means; pump means for forcing liquid from said tubthrough both said liquid distributing means comprising a rotatableimpeller having a center and a periphery supported on and driven by saiddriving means, said first liquid distributing means including a pumphousing portion surrounding said impeller and forming a part said firstdistribut- V of said first liquid distributing means; means fordirecting liquid flow adjacent said periphery to said first distributingmeans for high pressure distribution of liquid to said articles; andmeans for directing liquid from adjacent said center to said seconddistributing means for low pressure distribution of liquid to saidarticles comprising conduit means having an entrance adjacent saidimpeller center and an exit communicating with said second liquiddistributing means, said pump housing, first liquid distributing means,conduit means and second liquid distributing means being interconnectedfor joint rotation.

4. Article washing appartus, comprising: a liquid containing tub havinga bottom liquid collecting sump; a first article retaining means in saidtub adjacent said sump; a second article retaining means in said tubspaced above said first retaining means; first rotatable liquiddistributing means in said tub for distributing liquid over saidretaining means and articles retained therein located adjacent saidfirst retaining means; second rotatable liquid distributing means insaid tub for distributing liquid over said retaining means and articlesretained therein located adjacent said second retaining means; pumpmeans for forcing liquid from said tub through both said liquiddistributing means comprising a rotatable impeller having a center and aperiphery, both said liquid distributing means including a pump housingportion surrounding said impeller; means for directing liquid fiow fromadjacent said periphery to said first distributing means for highpressure distribution of liquid to said articles; and means fordirecting liquid from adjacent said center to said second distributingmeans for low pressure distribution of liquid to said articlescomprising conduit means having .an entrance adjacent said impellercenter and an exit communicating with said second liquid distributingmeans, and said pump housing, first liquid distributing means, conduitmeans and second liquid distributing means are interconnected for jointrotation.

References Cited UNITED STATES PATENTS 3,077,200 2/1963 Guth 134-1763,288,155 11/1966 Swetnam 134-176 3,288,156 11/1966 Jordan et al. 134176CHARLES A. VVILLMUTH, Primary Examiner.

ROBERT L. BLE'UTGE, Examiner.

